Improvement in photovoltaic conversion efficiency of InGaP solar cells grown on Si substrate by thermal cleaning using Si2H6

A new type of thermal cleaning for Si surfaces, using Si2H6, has been developed for growing GaAs buffer layers with an A-step surface on an Si substrate by metaloraganic vapor-phase epitaxy (MOVPE). This process made it possible, for the first time, to grow an A-step surface InGaP solar cell structure on an Si substrate with good surface morphology. An improvement in photovoltaic conversion efficiency has been achieved by this newly developed process.